Quoting Soaring1972 (Reply 3):But I find it hard to spot them during photoprocessing! How does a screener chek them?

We actually check for them in Screening by dragging the image in small circles and they are usually easy to spot with experience.

However, checking as a part of editing is very straightforward. Using the magic wand set at about 15, select the sky and equalise it and dust spots are then very difficult to miss, By going backwards and forwards you can deal with them with the clone or heal tool or, if there are a lot, create a duplicate layer and use that. You had one rejected on appeal a week or two ago where there was a massive spot (was it on a carrier deck ?)

Equalise just sky to reveal dust spots

Once you have finished, simply right click, Select inverse and sharpen, so avoiding sharpening the sky too

"You had one rejected on appeal a week or two ago where there was a massive spot (was it on a carrier deck ?)"
That is "right"!
But that was no DSLR, so normaly no dusk-spot on the chip possible!????!?!?! But that picture was rejected before with "scratch", but that was only a cable!